Testing of biological or chemical samples often requires a device for repeatedly subjecting multiple samples though a series of temperature cycles. To prepare, observe, test, and/or analyze an array of biological samples, one example of an instrument that may be utilized is a thermal cycler or thermocycling device, such as an end-point polymerase chain reaction (PCR) instrument or a quantitative, or real-time, PCR instrument. Such devices are used to generate specific temperature cycles, i.e. to set predetermined temperatures in the reaction vessels to be maintained for predetermined intervals of time.
Generally, it is desirable to increase the efficiency and output of the PCR process. Advances in automated biological sample processing instruments allow for quicker and more efficient analysis of samples. However, such automated systems often must be capable of integrating with other automated laboratory systems. Eliminating user interaction increases efficiency but requires the development of feedback controls to cue the main instrument controller that the next stage in the process is ready to occur. For example, the system must be sure that a sample holder is in place within the biological analysis system before activating the thermal cycling routine. In an automated system where there are no user interventions, it is desirable to cue the main instrument controller that the sample holder is in place based on feedback by the lab automation system.
A potential method to detect that the consumer plate in position is the use of an imaging system integrated into the main lab automation system. The imaging system may capture an image and, through complex algorithms, determine the presence of a sample holder on the sample block of the PCR system. Such a method is complex, costly, and tedious to implement. Other methods include the embedding of a sensitive load cell on the sample block module or the use of a barcode reader, which can detect the presence of the plate through a weight change or a barcode on the sample holder, respectively. However, such methods are costly to implement.
There is an increasing need to provide improved thermal cycler systems that address one or more of the above drawbacks.